UI test session on .NET 8 exits before the first test with an Activity type mismatch #141

Steps to reproduce

1. Run a RevitApiUiTest session with Nice3point.TUnit.Revit 2025.1.10 and TUnit 1.78.0 in Revit 2025 on .NET 8.
2. Include System.Diagnostics.DiagnosticSource 10.0 in the test output through Microsoft.Extensions packages.
3. Start the test session inside Revit.

✔️ Expected Behavior

The session starts and executes the registered tests.

❌ Actual Behavior

The session exits with code 10 before its first test.
TUnit.Engine throws MissingMethodException for System.Diagnostics.Activity TUnit.Core.Context.get_Activity().

TUnit.Core remains in the default context with DiagnosticSource 8.0.
TUnit.Engine loads into a separate context with DiagnosticSource 10.0.
The two contexts resolve different Activity types.